Heater system



L. P. HYNES.

HEATER SYST/EM.

APPLICATION FILED MAY2\,, me.

1,303,670. Patented May 13, 191!) 'IIIII nve/wtoz 361 alto anew I UNITED STATES PATENT OFFICE.

LEE P. HYNES, 0F ALBANY, NEW YORK, ASSIGNOR TO CONSOLIDATED CAR-HEATING COMPANY, OF ALBANY, NEW YORK, A CORPORATION OF WEST VIRGINIA.

HEATER SYSTEM.

Specification 01' Letters Patent.

Patented May 13, 1919.

Application filed May 21, 1918. Serial No. 235,770.

T 0 all whom it may concern:

Be it known that I, LEE P. HYNES, a citizen of the United States, and a resident of the city of Albany, county ofAlbany, and State of New York, have invented an-Improvement in Heater Systems, of which the following is a specification.

My present invention relates to heating devices for closed spaces, especially for cars; and more particularly for electrically operated railway cars in which the heating is effected by coils the resistance of which to the passage of current generates heat. It is especially designed to be used with thermo-' static regulating devices which openv the heater circuit when the temperature rises to a determinate point, and close it again when the temperature falls. In general, a mercury thermostat of special construction having contacts sealed in its tube is'employed. I do not particularly describe the device, because it is well known in this relation.

In my prior Patent No. 1,180,851, I have shown certain arrangements of circuits which in general may be modified to adapt them to the purposes of the present case, and in my later Patent No. 1,246,927, I have shown an improved arrangement, the advantages of which are set out upon page 2 at line 79 in that case. Both of these arrangements use an electro-magnetic main switch in the heater circuit which holds down against the opposition of a spring a contact closin the circuit by which current is transmitte from the trolley or other source to the heaters. The improved arrangement shown in the later of these two patents involves, however, the use of a tripping contact or second contact in the path of the armature of the relay there employed, such as is shown at 51-52 of Fi re 12 of the drawing of Patent No. 1,246,927.

The present invention is an improvement upon the constructions there outlined in that a drop of voltage and current in the thermostat circuit immediately at the time of the closing of the relay contacts, is obtained without any extra contacts or resistances; and also in that all automatic devices, such as the tripping contact employed in the second patent, a relay having only a single contact being employed. By this arrangement complication in the apparatus rendering it more difliare entirely dispensed with,

cult'to keep in'order is avoided, and other advantages are obtained.

The accompanying drawings show an embodiment of my invention;

Fig. 1 being a diagram of the circuits operatively connected and Fig. 2 being a simplified or skeleton diagram such as is often employed in laying out apparatus.

The two diagrams bear the same reference letters and in general a single description will suflice for both.

A is the trolley wire and A is the trolley. From the trolley a circuit leads to the heaters B, which passes through a coil 4 of a blow-out magnet and through the contacts 1, 2 of the main switch, contact 1 being carried upon the armature of the switch, and oontact 2 being shown as the fixed contact commonly employed, the contacts being held closed by magnet coil 7. A spring 11 tends to open the contacts.

A second circuit in shunt to the heater circuit passes from the trolley through the resistances R, R through the coil 7 of the main switch, and so to ground. The adjustment of the resistances is such that a sufiicientcurrent will pass through the coil to hold the contacts 1, 2 closed, so long as the switches are not altered. Thus, as long as the trolley is on the Wire, whenever the usual manually operated switch is closed by the car crew to bring the heater into action, contacts 1, 2, will be closed and the heater will receive current, provided the temperature of the car is lower than the setting of the thermostat, as will be hereafter described.

A third circuit, including the contacts 9 and 10 of the thermostat T and the coil 8 of the relay is arranged in multiple with resistanceR and coil 7 of the main switch. Resistance R is of substantial amountbeing in practice, on 550-volt'- circuits about 3800 ohms, although I do not mean to restrict myself in this particular. R is of relatively small value, say 100 ohms. 7 may be approximately 900 ohms, 8 of about 1200 ohms. When thermostat contacts 9 and 10 are open as above described (the car being cold and current being on the heaters owing to magnet coil 7 being ener ized and keeping contacts 1 and 2 closed no current is flowing through relay coil 8: but when the car warms up to the temperature set by the thermostat, contacts 9 and 10 close and current flows in the shunt circuit through'relay coil 8 and thermostat T to ground.

At the time of closure of contacts 9 and 10 this circuit is in shunt with both resistance R and coil 7, so that a relatively large current is shunted through relay coil 8. This attracts the armature in a positive manner and closes contacts 5 and 6. These contacts short-circuit coil 7, denergizing it and allowing contacts 1 and 2 to open and cut ofi the heaters. At the same time, by shortcircuiting coil 7, the double resistance of the circuit in shunt with coil 8 of the relay is greatly reduced, as only the relatively low resistance R is left in shunt. This further greatly reduces the current and voltage through relay coil 8 and thermostat T, though this is suflicient to maintain the relay contacts 5 and 6 closed as long as contacts 9 and 10 are closed. When they open, they have very little current to break. This is accomplished without any auxiliary contacts whatever.

It will be observed that the circuits are greatly simplified, and that there are only two sets of contacts in the whole apparatus, outside of the thermostat contacts; while as these are sealed within the glass and carry only very small currents at moderate voltages, they require no inspection or attention whatever. I am thus enabled to obtain all of the advantages of the former constructions, and in addition greatly to simplify and cheapen the apparatus.

I have not shown the mechanical details,

since appliances well known and easily purchased on the market may be employed.

Changes may obviously be made in the arrangements pointed out without departing from the invention, and such changes I aim to embrace in the claims.

I claim as my invention:

1. In a heating system, a source of current, heaters, and three parallel circuits, one containing the heaters and the contacts of an electro-magnetic main switch held normally closed by current in the switch coil; another containing a high resistance and an operating coil for the main switch in series therewith; and a third containing a high resistance in series and a low resistance in shunt to the operating coil of a single-contact relay controlling the coil of the main switch, and a thermostat in series with and controlling the coil of the relay.

2. In a heating system, a source of current, heaters, a main circuit including the heaters and contacts held normally closed by the current; in combination with a shunt circuit, a magnet coil in the shunt circuit for operating the contacts in the heater circuit and a resistance in series with the magnet coil, a second shunt circuit including a single contact relay and thermostat, the second shunt circuit being in series with a part of the resistance and in shunt with part thereof; the relay controlling the magnet coil, and the thermostat controlling the relay.

3. In a heating system, a source of current, a main circuit to ground including heaters, contacts in said circuit, and an electro-magnet coil which when energized holds such contacts normally closed; in combination with a high resistance circuit in shunt to the main circuit and including said magnet coil, and a single-contact relay and thermostat in a circuit in shunt to the magnet coil, the relay contact -controlling the magnet coil, and the thermostat controlling the relay.

4. In a heating system, heaters, a single contact 'electro-magnetic contactor controlling the heaters, a single contact relay controlling the contactor, and a thermostat-controlling the relay; the arrangement being such that the voltage of the thermostat circuit is lowered when the relay contact closes.

5. In a heating system, a source of current, a main circuit from the source of current containing the heaters and the contacts of an electromagnetic contactor; a second circuit containing in the order named, a high resistance, a low resistance and the coil of the contactor, and a third circuit containing the coil of a single contact relay, a thermostat and the said high resistance.

6. In a heating system, a source of current, a main circuit from the source of current containing the heaters and the contacts of an electromagnetic contactor; a second circuit containing in the order named, a 1

high resistance, a low resistance and the coil of the contactor; a relay coil circuit containing the coil of a relay controlling the circuit of and in shuntto the main contactor coil and a thermostat in series with the relay co1 7. In a heating system, a source ofcurrent, a main circuit from the source of curandthe contacts of an electromagnetic contactor; a second circuit connected to the source of current containing in the order named, a high resistance, a low resistance and the coil of the contactor; and a third circuit containing a relay coil and a thermostat in series, said circuit being in shunt to the low resistant-sand the main contactor coil in series when the contacts of the relay are open and in shunt*only to the low resistance when the relay contacts are closed.

9. In a heating system, a source of current, heaters, a main of current through the heaters to ground, contacts in said circuit, and an electro-niagnet holding said cont-acts normally closed; in combination with a circuit through the elect-ro-magnet in shunt to the main circuit,

circuit from the source a resistance in said circuit, a single-contact relay the coil of which is in shunt to the electro-magnet and in series with a thermostat controlling said relay, a resistance in series with the relay coil, and a resistance in shunt thereto; the closing of the contacts of the relay short-circuiting the electromagnet and thus opening the heater circuit.

In testimony whereof, I have si ed my name to this specification this 17th day of May, 1918.

LEE P. HYNES. 

